<!-- alert.vue -->
<template>
    <div class="alert">
        <div class="alert-main" v-for="item in notices" :key="item.name">
            <div class="alert-content">{{ item.content }}</div>
        </div>
    </div>
</template>
<script>
let seed = 0;
function getUid(){
    return `alert_${seed++}`
}
export default {
    data() {
        return {
            notices: [],
        };
    },
    methods: {
        add(notice){
            const name = getUid();
            let _notice = Object.assign({ name }, notice);
            this.notices.push(_notice);
            
            const duration = notice.duration || 3000;
            setTimeout(() => {
                this.remove(name)
            }, duration);
        },
        remove(name){
            const notices = this.notices;
            
            const index = notices.findIndex(item => item.name === name);
            this.notices.splice(index, 1)
        }
    }
};
</script>
<style>
.alert {
    position: fixed;
    width: 100%;
    top: 16px;
    left: 0;
    text-align: center;
    pointer-events: none;
}
.alert-content {
    display: inline-block;
    padding: 8px 16px;
    background: #fff;
    border-radius: 3px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.2);
    margin-bottom: 8px;
}
</style>
